1. Field of the Invention
This invention relates to a novel metal roof unit of a unitary box-like structure comprising a backing, a surface metal plate, a heat insulating material disposed integrally between the backing and the metal plate, and a joint member provided along its longitudinal direction.
2. Description of the Prior Art
Conventional roofing materials include, for example, clay rooftile, galvanized sheet iron, pressed cement rooftile and cement rooftile. However, all of these are only materials for roof covering, and in actual roofing works, roofers use such a material together with separately provided other roofing materials, a heat insulating material and a water-proof device and lay roofs with their special skill and great efforts.